Intake manifold pressure responsive fuel injection system



Feb. 10, 1970 R. ALDERSON 3,

INTAKE MANIFOLD PRESSURE RESPONSIVE FUEL INJECTION SYSTEM 2 Sheets-Sheet1 m mh INVENTOE EDW/A/RAZDEQSO/V 5 QRNEV Q w m E e m J Q. m ow O F Feb.10, 1970 R; ALDERSON v 3,494,337

INTAKE MANIFOLD PRESSURE RESPONSIVE FUEL INJECTION SYSTEM Filed June 24,1968 8 I INVENTOIE 1 [aw/m2 Amz-Psav I'M- H I BY XM A ORNEY UnitedStates Patent INTAKE MANIFOLD PRESSURE RESPONSIVE FUEL INJECTION SYSTEMEdwin R. Alderson, Decatur, Ill., assignor to Borg- Warner Corporation,Chicago, lll., a corporation of Delaware Filed June 24, 1968, Ser. No.739,349 Int. Cl. F02d 11/08, 1/04, 1/06 US. Cl. 123103 8 Claims ABSTRACTOF THE DISCLOSURE A fuel injection system including a fuel meteringarrangement responsive to engine intake manifold pressure. A fueldelivery control mechanism including a throttle controlled modulationvalve is responsive to throttle position and provides a modifying signalwhich alters the normal metering signal. By this action, the fuel rateat a given intake manifold pressure is increased providing additionalfuel for that position of the engine throttle.

Background of the invention This invention relates to a controlmechanism for an internal combustion engine fuel delivery system. Moreparticularly, it relates to a throttle actuated modulator valve forvarying fuel delivery rate of a fuel injection system.

In certain types of fuel injection systems such as those shown in UnitedStates Patents 2,984,232, 3,100,449 and 3,149,619, intake manifoldpressure is used as a signal to control the fuel delivery rate. As themanifold pressure varies, the fuel delivery rate is proportionatelyaltered.

For certain operating conditions, control of fuel delivery rate solelyin proportion to intake manifold pressure provides satisfactory engineperformance. However, in general, engine fuel demand is affected byother operating parameters such as engine speed, and engine load.Additionally, operational characteristics of the fuel injectors, fueldelivery and metering apparatus, and the control servo-mechanism allcontribute to the establishment of a non-linear relationship :betweenintake manifold pressure signal and actual fuel demand at a particularspeed and load. For these reasons, the fuel rate needed for properengine operation at a given load point may not be reflected by theintake manifold signal received. That is to say, the same intakemanifold signal, and consequently, the same fuel rate, may be obtainedat various combinations of speed, load and throttle position. This fuelrate, however, may be the most desirable for only one of these variousoperation positions. It is desirable therefore, to provide anarrangement for modulating the manifold pressure signal in order tocompensate for the effects of the other engine parameters mentioned.

As is well known, the principal control mechanism for an internalcombustion engine is the throttle. It has been found that modulation ofthe intake manifold signal in relation to throttle fly position providesan effective solution to the problem of proper fuel delivery under alloperating conditions.

Accordingly, it is the principal object of the present invention toprovide an improved fuel delivery system which effectively modulates thefuel metering signal in response to throttle fly position.

Summary of the invention A modulator valve is provided which isresponsive to engine throttle fly position to vary the signal receivedby the fuel metering arrangement. This valve introduces a signal whichmodulates the sensed manifold pressure 3,494,337 Patented Feb. 10, 1970signal to produce a combined signal providing increased fuel rate at agiven intake manifold pressure.

Particular objects and advantages of the present invention will becomemore readily apparent with reference to the following description andaccompanying drawings.

Description of the drawings FIGURE 1 is an elevational view, partly insection, and partially schematic, of an apparatus illustrating variousfeatures of the present invention;

FIGURE 2 is a plan view of a portion of the apparatus of FIGURE 1;

FIGURE 3 is a fragmentary view, partly in section, illustrating analternate position of a portion of the apparatus of FIGURE 1; and

FIGURE 4 is an elevational view of a part of the apparatus of FIGURE 1illustrating particular details of the apparatus.

Detailed description Referring now to the drawings there is shown a fueldelivery control arrangement for an engine having a fuel injectionsystem which is illustrative of the principles of the present invention.

As best seen in FIGURE 1 the fuel delivery system generally designated10 is associated with an engine including an intake manifold 12 and athrottle or air valve 14. The system includes a fuel tank 16, a fuelinjection metering and delivery pump 18, a metering servo 20 and amodulator valve 24.

The throttle valve 14 includes a generally vertical throat 26 extendingbetween an inlet air filter assembly 28 and the intake manifold. Anaperture 30 is provided in the manifold to allow passage of air from thethroat 26 to the manifold for distribution to the engine combustionchambers.

A throttle fly 32 is pivotally supported within the throat 26 upon anactuator shaft 34 which extends outwardly of the throat. The fly 32 isoperatively connected to a linkage 36 (see FIGURES 2 and 3) including alever arm 38, to which is pivotally connected a motion transfer lever 40associated with the accelerator (not shown) of a vehicle. Movement ofthe accelerator by the operator of the vehicle will therefore beeffective to position the throttle fly for proper air flow through thethrottle valve throat 26.

The linkage 36 also includes a curved following lever 42 secured to theshaft 34 for rotation therewith. An adjustable turn-buckle type link 44(see FIGURE 4) is pivotally secured to the lever 42 and is operativelyconnected to the modulator valve 24 for purposes as will become apparentshortly.

The throttle valve 14 additionally includes a retention flange 46defining a transverse passage 48 communicating with the throat 26downstream of the throttle fly.

Turning again to the fuel delivery control system 10, the fuel meteringand delivery pump 18 is adapted to receive fuel from the tank 16 andaccomplish controlled distribution of metered quantities of fuel to aseries of injectors (not shown) through delivery lines 50 (only one ofwhich is shown). The fuel is metered by the servo 20 which moves inresponse to a manifold pressure signal to position a cam (not shown)connected to an operator shaft 52. This movement in turn controls thepump delivery volume to provide a metered fuel charge. These systemelements are well known in the art and representative arrangements areshown in United States Patents 2,984,232; 3,100,449, and 3,149,619. Theimportant factor to be noted is that the fuel is metered in response toa sensed manifold pressure signal.

The metering serve 20 is in communication with a manifold pressuresignal through a conduit 54 connected between the servo and themodulator valve 24.

The modulator valve, best seen in FIGURES. 1 and 2, includes a housing56, conduit couplings 58 (see FIG- URE 2) and 60 and spool 62.

The housing includes a mounted flange 63 secured to the retention flangeof the throttle fly in overlying relation to the transverse passage 48.This flange 63 includes aperture 64 open to the interior of the housing.An orifice plate 65 is secured to the flange 63 and includes arestricting orifice 66 communicating between the passage 48 and theinterior of the housing 56 through the aperture 64.

The housing 56 is divided into a manifold signal receiving chamber 67adjacent the aperture 64 and a modulating signal receiving chamber 68 bya pair of spaced apart inwardly directed sealing lands 70. A pair ofspaced apart support hubs 72, best seen in FIGURE 2 are provided ingeneral alignment with the lands. These hubs rotatably support the valvespool 62.

The conduit coupling 58 is connected to one of the hubs as shown inFIGURE 2. This hub includes an appropriately formed receptacle. Thiscoupling is also connected to the conduit 54 extending between the servo20 and the modulator valve 24. The other conduit coupling 60 isconnected to the portion of the housing forming the modulation signalreceiving chamber 68.

Each coupling includes a central passageway in communication with theinterior of the housing 56. Thus the servo 20 is in communication withthe interior of the modulator valve housing at the hub 72 and thechamber 68 is in communication with the atmosphere through the coupling60. The coupling 60 may, if desired, be connected to a conduit (notshown) which extends into the intake air filter 28 to preventintroduction of contaminated air into the system.

The valve spool 62 is generally cylindrical in shape and is rotatablysupported within the hubs 72. A shaft portion 76 extends from anappropriate opening in the hub 72 and is provided with a lever 77connected to the turnbuckle link 44. Movement of the throttle fly 32therefore causes corresponding movement of the spool 62.

The diameter of the spool 62 is approximately equal to the distancebetween the sealing lands 70 so that the spool effectively seals thechamber 67 from the chamber 68.

The valve exterior diameter is provided with a flat 78 which, whenaligned with one of the sealing lands 70, defines a port 80communicating between the chambers 67 and 68, as best seen in FIGURE 3.

As can be appreciated, rotation of the valve spool 62 between the closedposition shown in FIGURE 1 and the open position shown in FIGURE 3varies the effective orifice size of the port 80 to produce variableflow between the chamber dependent upon the particular position of thespool 62.

The spool 62 additionally includes a longitudinal passage 82 open at thehub 72 which includes the coupling 58. A transverse passage 84 isprovided which is in communication with the passage 82 and open at theflat 78. Appropriate seals are provided between the housing hubs 72 andthe spool 62 to prevent leakage between the chambers 67 and 68 when thevalve is in the closed position or leakage between the hub 72 containingthe coupling 58 and the chamber 68.

When the spool 62 is in the closed position, a manifold pressure signalis communicated to the servo 20 through the restricting orifice 66, theaperture 67, the passages 82 and 84 of the spool 62, the coupling 58 andthe conduit 54. So long as the spool remains in the closed positionengine fuel rate will be determined by intake manifold pressure.Variations in the manifold pressure 'will therefore producecorresponding variations in fuel delivery rate.

When the spool 62 is positioned such that the fiat 78 is aligned withthe opposing sealing land 70 to define the port 80 communicating betweenthe chambers 68 and 67 a modified signal is produced. Atmosphericpressure .is communicated to the transverse passage 84 through the portto modify the sensed manifold pressure signal. Since the manifoldpressure is below atmospheric pressure the combined signal will beincreased, resulting in an increased fuel delivery rate.

It is of the utmost importance that the modulation of the manifoldpressure signal takes place at the appropriate condition of engineoperation. For that reason, the spool 62 of the modulator valve 24 isconnected through the turn-buckle link 44 to the throttle fly linkage.Thus movement of the throttle fly 32 produces corresponding movement ofthe modulator valve spool between its closed and open positions.

The link 44 is adjusted to establish the proper relationship betweenthrottle fly position and spool position to produce initiation of themodulation signal at the proper time.

Experience with the injection systems described in the previouslymentioned patents has shown that at a given load there is a tendency forthe system to go lean as engine speed is increased. That is to say, thefuel output per stroke of the injection pump at a given intake manifoldpressure will decrease as engine speed is increased. By modulating thefuel control signal in response to throttle fly opening, the output ofthe pump can be increased to produce the desired fuel delivery rate.

The relationship between size of the restricting orifice 66, diameter ofthe passage in the conduit coupling 60 and the set length of theturn-buckle type link 44 determine the modulation characteristics of thevalve. The link 44 is adjusted to establish the point of opening of thevalve with respect to throttle fly position. The size of the restrictingorifice 66 controls the vacuum rate and thereby determines the amount ofmodulating signal admitted into the system. This is true because of thepressure difference across the orifice 66 provides for flow of themodulating signal air into the throttle valve throat 26 and the orificesize determines the maximum flow rate. The size of the passage in theconduit coupling 60 in turn determines the maximum modulating air flowrate by limiting the air source. By adjusting these elements, a systemof modulation can be established which provides a fuel delivery signalprecisely matched to the engine fuel requirements throughout the entirerange of speed and load.

Various features of the invention have been particularly shown anddescribed in connection with the illustrated embodiment of theinvention. However, it must be understood that these particulararrangements merely illustrate and that the invention is to be given itsfullest interpretation within the terms of the appended claims.

What is claimed is:

1. In a fuel injection system for an internal combustion engine, a fueldelivery control mechanism including, a servo responsive to a pressuresignal to control engine fuel delivery rate, a modulator valve includinga housing defining a manifold signal receiving chamber and a modulatingsignal receiving chamber, said valve including means for connecting saidmanifold signal receiving chamber with a source of engine intakemanifold pressure, and means for connecting said modulating signalreceiving chamber with the atmosphere, said valve further including aspool disposed intermediate said chambers movable between a closedposition separating said chambers and at least one open positionproviding communication therebetween, said spool including a passagecommunicating with said manifold signal receiving chamber when saidspool is in said closed position and in communication with both saidchambers when in said open position, a conduit connected to saidmodulator valve and said servo communicating between said passage insaid spool and said servo, and a linkage connected to said spool toeffect movement between said closed and open positions, said linkagebeing adapted for connection to a throttle fly of said engine to movesaid spool in response to movement of said throttle fly.

2. A fuel delivery control mechanism as claimed in claim 1 wherein saidspool is movable between said closed position and a plurality of openpositions providing varying degrees of communication between saidchambers.

3. A fuel delivery control mechanism as claimed in claim 2 wherein saidhousing includes a pair of spaced apart sealing lands disposedintermediate said chambers and said spool is generally cylindrical andsized to sealingly engage said lands when in said closed position, saidspool further including a fiat formed on the exterior thereofpositionable with respect to one of said lands upon movement of saidspool to define a port between said fiat and said land providingcommunication between said chambers.

4. A fuel delivery control mechanism as claimed in claim 3 wherein saidmeans connecting said manifold signal receiving chamber with a source ofengine intake manifold pressure includes a restricting orifice, saidmeans communicating said modulating signal receiving chamber with theatmosphere including a coupling including a passage therethrough, andwherein said linkage includes an adjustable turn-buckle type link.

5. A fuel injection system for an internal combustion engine having anintake manifold, an air throttle secured to said intake manifoldincluding a movable throttle fly for controlling the passage of intakeair through said air throttle, said fuel injection system including afuel delivery and metering pump, a fuel delivery control mechanism tocontrol the fuel delivery rate comprising; a servo responsive to apressure signal to control engine fuel delivery rate, a modulator valveincluding a housing defining a manifold signal receiving chamber and amodulating signal receiving chamber, said valve including meansconnecting said manifold signal receiving chamber with a source ofengine intake manifold pressure, and means connecting said modulatingsignal receiving chamber with the atmosphere, said valve furtherincluding a spool disposed intermediate said chambers movable between aclosed position separating said chambers and at least one open positionproviding communication therebetween, said spool including a passage incommunication with said manifold signal receiving chamber when saidspool is in said closed position, and in communication with both saidchambers when in said open position, a conduit connected to saidmodulator valve communicating between said passage in said spool andsaid servo and a linkage connected to said spool to effect movementbetween said closed and open positions, said linkage being connected tosaid throttle fiy of said engine to move said spool in response tomovement of said throttle fly.

6. A fuel injection system for an internal combustion engine as claimedin claim 5 wherein said spool is mov able between said closed positionand a plurality of open positions providing varying degrees ofcommunication between said chambers.

7. A fuel injection system for an internal combustion engine as claimedin claim 6 wherein said housing includes a pair of spaced apart sealinglands disposed intermediate said chambers and said spool is generallycylindrical and sized to sealingly engage said lands when in said closedposition, said spool further including a fiat formed on the exteriorthereof positionable with respect to one of said lands upon movement ofsaid spool to define a port between said flat and said land providingcommunication between said chambers.

8. A fuel injection system for an internal combustion engine as claimedin claim 7 wherein said means connecting said manifold signal receivingchamber with a source of engine intake manifold pressure includes arestricting orifice, said means communicating said modulating signalreceiving chamber with the atmosphere including a coupling including apassage therethrough, and wherein said linkage includes an adjustableturnbuckle type link.

References Cited UNITED STATES PATENTS 2,132,445 10/ 1938 Schweizer.2,659,354 11/1953 Nicolls. 2,702,029 2/ 1955 Burton. 2,727,504 12/ 1955Peras. 2,751,897 6/1956 Schweizer et a1. 2,821,372 1/1958 Nystrom et al.2,841,131 7/ 1958 Zupancic. 2,849,999 9/ 195 8 Morris. 2,984,232 5/1961Arndt. 3,100,449 8/ 1963 Dahl.

WENDELL E. BURNS, Primary Examiner US. Cl. X.R.

